Identification of four material phases in bitumen by atomic force microscopy

ABSTRACT The identification of material phases at the so called bitumen-scale in context of multiscale modeling of asphalt is presented. For this purpose, atomic force microscopy (AFM), providing insight into the surface topography and mechanical properties, is applied to different types of bitumen. Based on the obtained AFM results, four different material phases at the bitumen-scale are identified. These phases are related to the chemical composition of bitumen, characterized by a wide range of molecular mass. Within the anticipated multi-scale model, the properties of these phases serve as input for upscaling, providing material parameter of the bitumen phase at the next-higher scale, i.e., the mastic-scale. KEYWORDS: bitumenmulti-scaleatomic force microscopypulsed-force modenon-contact mode